Chapter 13. How To

I've not put a lot of explanations in the procedures. Refer to the Cacti manual for more details.

Have a tested script ready to go. I used the following script located in

/home/cactiuser/bin

called

random2.pl

:

#!/usr/bin/perl  w

print int(rand(10));

This script simply prints out a random integer between 0 and 9 every time it's called.

The minimal steps to create a graph from a script are simply:

1. Create a Data Input Method to tell Cacti how to call the script and what to expect from it.

2. Create a Data Source to tell cacti how and where the data will be stored.

3. Create a Graph to tell cacti how the data will be presented in graph form.

4. Add Graph to Graph View so you can view the graph.

5. View the Graph

The details are below:

1. Create Data Input Method

Click the Console tab at the top

Click Data Input Methods under Management

Click Add

Name: Random 2 Input

Input Type: Script/Command

Input String: /home/cactiuser/bin/random2.pl

Click Create

Should see "Save Successful." at the top of the page.

Click Add by Output Fields (there are no input fields for this example)

Field [Output]: random_number

Friendly Name: Random Number

Update RRD File: checked

Click Create

Should see "Save Successful." and random_number listed under Output Fields.

Click Save

Should see "Save Successful." and Random Input listed in Data Input Methods.

2. Create a Data Source

Click Data Sources under Management

Click Add in the top right

The Data Template Section should be None and None, we're not using templates for this example.

Click Create.

Name: random2ds

Data Source Path: blank (Cacti will fill this in)

Data Input Source: Random 2 Input (this is the data input method you created in step 1)

Highlight each of the Associated RRA's using control click

Step: 300 (300 seconds = 5 minutes)

Data Source Active: checked

Describe the Data Source Item inside the RRA by...

Internal Data Source Name: random_number

Minimum Value: 0

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